I have said it before: there are many parts of the "conventional" OS which are outdated or simply broken (POSIX in particular is horrible). Incremental backwards compatible improvement can only go so far.
Google certainly has the resources to do something new. Their changes will never be accepted in the mainline, so it is understandable if they don't want to bother with it.
I can't imagine how a business which has immediate goals with timing, which has to release a product, etc, coordinates pushing all of its patching into the mainline. It has to be a tremendous PITA:
- first they have to release their product with a custom kernel. This kernel has to be supported for the life of the product.
- some indeterminate time in the future, some of their patches will hopefully be accepted in the mainline, probably in a modified form.
- now a new custom different custom kernel has to be created and also maintained.
It is madness. I perfectly understand why most embedded vendors don't do it and why Google doesn't bother with it.
Also, as trollish as it may sound, the comparable stability of the Windows kernel and ABI-s sometimes seems like heaven compared to this nightmare.
Don't get me wrong - I use and recommend Linux all the time - but I am trying to be objective here.